A ORCHARD PRANT RICE II 
ber of the over-winter lice perish, but a few find sufficient protection 
to enable them to ufithstand the cold and they start new colonies 
in the spring. Our tanglefoot bands have caught large numbers 
of these lice upon the lower half in the spring, and enormous num¬ 
bers in the upper half in the fall. 
PARTS OP TRpp MOST ATTACKED. 
A great deal of digging about the trees in orchards of the 
Western slope proved that very little harm is done to roots that 
are more than lo inches below the surface of the soil, and more 
than three feet from the crown of the tree. If water sprouts are 
allowed to grow up about a tree, they are almost sure to be very 
lousy, especially just at the ground. 
Succulent and rapidly-growing parts, especially grafts, are very 
susceptible to attack. 
Of all the varieties grown in Colorado, the Missouri Pippin 
seems to be worst infested, and Northern Spy is practically ex¬ 
empt. We have yet to find a single tree of this latter variety much 
infested. In a few instances slight infestation has been found in 
pears. 
'Loose, porous soils seem more favorable for the development 
of this louse upon the roots than are the heavier and more com¬ 
pact soils. 
INJURIES. 
The woolly aphis belongs to a gall-producing group of plant 
lice. Their punctures in the bark have an irritating or poisoning 
effect, which results in an increased fiow of sap, which is to the 
advantage of the louse, and at the same time it causes an abnor¬ 
mal growth of the part. Very small rootlets may have lumpy galls 
of considerable size (Plate III, Fig. 4), and larger roots may have 
an aggregation of these swellings involving a large portion of the 
root surface. As a result of these attacks, the roots often die 
and rot and sometimes the condition is so bad that a tree may be 
pushed or blown over because of the number of roots that have 
died near the crown of the tree. When the lice attack the tender 
bark about a scar, upon trunk or limb, the new growth is made 
more or less gnarly, but the effect is not so pronounced as upon 
the roots. The lice also attack the tender bark of the small limbs, 
and particularly where rapid growth is taking place, so that grafts 
and water sprouts are usually worse infested than other portions 
of the tree. Upon these rapidly growing parts the lumpy growths 
often become very numerous. The galls are usually smooth but 
often crack open, and especially is this true in cases of severe in¬ 
festation. 
